This invention relates to the field of processes for cleaning refinery equipment. More specifically, the invention relates to the field of cleaning the internal surfaces of dynamic devices in refineries, such as centrifugal pumps and control valves and other like devices.
After a period of use of a pump or control valve in a refinery, contaminants may develop on its moving and other parts. This impedes performance. In order to maintain performance at an acceptable level, these contaminants must be removed.
The contaminants removed would include any hydrocarbon that is found in crude oil. These hydrocarbons will vary in size, length, molecular weight and structure. The industry refers to these different structures as Light End, Medium and Heavy. Light Ends would be cuts like methane, propane, and ethane. Medium cuts would include kerosene, gasoline, and diesel, among others. Heavy cuts would include lubricants, waxes and asphalt.
The conventional method for cleaning dynamic devices involves complete disassembly of the dynamic device followed by manual cleaning. Where this device is centrifugal pump, this involves turning off the power, isolating the pump from the process stream, opening the casing, removing the impeller and all the other individual parts, and then manually cleaning each of the contaminated parts (o-rings, seals, separator plate, motor adaptor, rotating element, etc.) individually. The disassembly and cleaning steps are extremely labor intensive, expensive, and require a long shut-down period. Once everything has been cleaned, the user must then reassemble. This also takes a considerable amount of time.
The present invention overcomes these disadvantages by introducing a cleaning agent into the device using steam. The steam volatilizes the cleaning agent and quickly dissolves the organic residues from inside the dynamic device. During the cleaning process, the device is temporarily activated. This has been shown to improve the cleaning process. The cleaning agent used is comprised of terpene and surfactant.